Genetically Programmed Bacteria Grow Into Electronic Devices

For folks that fear the consequences of genetic engineering and related fields, it’s time to dial it up to eleven. That’s because researchers at Duke University have now demonstrated that they’re able to genetically modify bacteria to coax them to produce electronic devices, potentially leading to a new and surprising way for to interface with our bodies. The investigators’ first device is a bacterial pressure sensor that, when squeezed, generates enough current for easy detection.

Previously, similar research has relied on scientists to guide the growth of a bacteria using containers of different shapes or via external stimuli such as electricity. The new development involves programming the growth of the colony directly into the DNA of the bacteria, what is known as a “synthetic gene circuit,” and manipulating the nutrients supplied to it to produce the desired size and shape of the final object.

In order to make the final result into an electronic device, the bacteria are fed a diet rich in gold nanoparticles. These nanoparticles get distributed throughout the colony as it grows, and provide the electric conductivity necessary to make electronics.

Some details according to Duke University:

The genetic circuit is like a biological package of instructions that researchers embed into a bacterium’s DNA. The directions first tell the bacteria to produce a protein called T7 RNA polymerase (T7RNAP), which then activates its own expression in a positive feedback loop. It also produces a small molecule called AHL that can diffuse into the environment like a messenger.

As the cells multiply and grow outward, the concentration of the small messenger molecule hits a critical concentration threshold, triggering the production of two more proteins called T7 lysozyme and curli. The former inhibits the production of T7RNAP while the latter acts as sort of biological Velcro that can latch onto inorganic compounds.